by AHF » Thu Oct 22, 2015 9:19 pm
Gunther,
In Harbour indexes we have 2 kind of functions.
1st the ones we are obliged to use because we must have only one data type in the index expression. The big part!
These are conversion data type functions that is not needed in ADO :sort thus adordd extracts the fields and is straight forward. You dont need to worry about these and do not need to be included in SET UDFS. ( EX. DTOS, DTOC, STR, VAL, ETC)
2nd the ones that alter the index expression value for ex SUBSTR or IF( fieldvalue, "1", "2" ) var evaluation & true User Defined Functions.
These we have to declare as UDFS because they need to be evaluated by Harbour and they can not be evaluated by Sort .
Is it clear for you?
Regards
Antonio H Ferreira